【Discourse】 , 【expatiate】 , 【dilate】 , 【descant】 are comparable when meaning to talk or sometimes write more or less formally and at length upon a subject.
【Discourse】 frequently implies the manner or attitude of the lecturer, the monologist, or the preacher; it may suggest detailed or logical and sometimes profound, witty, or brilliant discussion.
【Expatiate】 implies ranging without restraint or wandering at will over a subject; it connotes more copiousness than 【discourse】 and often carries a hint of long-windedness.
【Dilate】 implies a discoursing that enlarges the possibilities of a subject (as by dwelling on each small detail).
【Descant】 stresses free comment, but it often also connotes delight or pleasure in this free expression of one’s opinions or observations.
2015年11月29日 — The role of speech content in the assessment of candidate oral performance ... the syntactic structure of descriptors, and expatiate on the.
Y. Cheng, Discourses of Race and Rising China, Mapping Global Racisms, ... Chinese Shops and the Formation of a Chinese Expatriate. Community in Namibia.